Aseptic packaging installation having aseptic buffer zones

ABSTRACT

An aseptic packaging installation in individual containers, comprising a stand on which there is mounted an enclosure ( 3 ) that has a floor ( 4 ) with an overhead ceiling ( 6 ) and that receives at least one rotatable platform ( 7 ) in a packaging zone (Z 1 ) subjected to a sterile laminar stream flowing vertically from the ceiling of the packaging zone at a rate that is adapted to establish in the packaging zone a first pressure (P 1 ) that is greater than the surrounding pressure, the installation being characterized in that the enclosure is provided with laminar stream exhaust means for removing the laminar stream from the packaging zone via a buffer zone extending between the packaging zone and the floor.

BACKGROUND OF THE INVENTION

It is known that in order to ensure long-term preservation of foodstuffs without subjecting them to particular refrigeration conditions, it is necessary for the foodstuffs to be packaged in aseptic manner, i.e. without germs being introduced into the container during the various stages of packaging. So as to ensure packaging is aseptic, it is known in particular that it is necessary to subject the line of machines performing packaging to a sterile environment that is generally obtained by causing a laminar filtered stream of air to flow vertically over the line of machines.

To this end, existing aseptic packaging installations, as described in particular in document FR-A-2 800 710, comprise a cabin forming around the line of machines a packaging zone presenting a high degree of asepsis, at least one side of the packaging zone being beside an operator zone that is maintained at a lower degree of asepsis than the packaging zone proper by providing a stream of air flowing from the packaging zone towards the operator zone through openings in a partition common to the packaging zone and to the operator zone. In addition, document EP 1 251 085 describes chambers forming a packaging zone at a pressure that is higher than atmospheric pressure, surrounded by an enclosure at atmospheric pressure forming an operator zone.

Aseptic packaging installations are particularly well adapted to filling containers in the form of tubs thermoformed in a strip of thermoplastic material since driving the strip of tubs in the installation does not require any movable parts in the enclosure.

In contrast, installations having carousels and/or rotating platforms, dedicated to filling bottles and other containers of that type, present various constraints, in particular relating to movement of the containers due to the fact that the containers are individual and independent from one another. In such an installation, the containers are filled and closed while they are received on rotary platforms driving said containers along circular trajectories. A rotary platform is generally constrained to rotate with a column mounted so as to pivot on a stand of the installation and that has a bottom end linked in rotation with a rotary drive element such as a gear train. In order to implement packaging aseptically, it is currently necessary to dispose all of the platforms inside an enclosure, the column of each platform passing through a table that separates said platform from its rotary drive elements by constituting a portion of the floor of said enclosure. It is necessary to provide dynamic sealing elements between the table and the column. Implementing said dynamic sealing is made difficult by being positioned inside the aseptic zone. That complicates production, upkeep, and maintenance of the installation.

OBJECT OF THE INVENTION

An object of the invention is to provide an aseptic packaging installation that minimizes the risk of pollution inside the packaging zone, while being simpler to make and maintain.

SUMMARY OF THE INVENTION

To this end the invention provides an aseptic packaging installation in individual containers, comprising a stand on which there is mounted an enclosure that has a floor with an overhead ceiling and that receives at least one rotatable platform in a packaging zone subjected to a sterile laminar stream flowing vertically from the ceiling of the packaging zone at a rate that is adapted to establish in the packaging zone a first pressure that is greater than the surrounding pressure, the installation being characterized in that the enclosure is provided with laminar stream exhaust means for removing the laminar stream from the packaging zone via a buffer zone extending between the packaging zone and the floor.

Thus, two zones are defined inside the enclosure, namely: a packaging zone in which the containers are treated (the treatment may for example be filling and/or closing the containers), and a buffer zone in which the aseptic constraints are less severe than those relating to the packaging zone so that the presence of dynamic sealing elements in the buffer zone is less problematic. In addition, it has been observed that the efficiency of the sterile laminar stream for maintaining aseptic conditions is best when it exits in uniform manner, with a minimum of disturbance.

Advantageously, the installation includes dispersion means for dispersing at least one cleaning substance and recovery means for recovering said substance, at least a portion of the dispersion means and the recovery means extending into the buffer zone.

This makes it possible to limit as much as possible the presence in the packaging zone of elements having outside surfaces that can collect germs and that must be cleaned.

Preferably, the dispersion means comprise washing substance dispersing nozzles that open out into the packaging zone and into the buffer zone and/or the dispersion means comprise decontamination substance dispersing nozzles that open out into the packaging zone and into the buffer zone.

In a particular embodiment, the recovery means comprise at least one substance collection tray extending into the buffer zone.

The tray thus recovers waste water from the enclosure while being outside of the packaging zone, and that facilitates the design of the installation and maintenance operations.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention appear on reading the following description of a particular, non-limiting embodiment of the invention.

The description is made with reference to the accompanying sole figure showing in section an installation of the invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the figure, the aseptic packaging installation shown is designed for packaging a substance in containers (not shown). The installation includes a stand 1 carrying a line of machines 2 (only one of which is shown in the figure), such as filler machines, cap heat-sealing machines, and stopper insertion machines, and an enclosure 3 surrounding the machines and comprising a floor 4, walls 5, and a ceiling 6.

Each machine 2 includes a platform 7, provided with container treatment means, which is constrained to rotate with a column 8 mounted to rotate on the stand 1. A stationary table 11 extends under the platform 7 in a position that is spaced apart therefrom and that has the column 8 passing therethrough. Under the table 11, the column 8 has a portion 9 for connection to rotary drive means 10.

The platform 7 of each machine 2 extends into a packaging zone Z1 that is defined inside the enclosure 3 and that is subjected to a sterile laminar stream (represented by the arrows in the figure) flowing vertically from the ceiling 6 at a rate that is adapted to establish a first pressure P1 in the packaging zone Z1, which first pressure P1 is greater than the pressure P surrounding the installation. The laminar stream is produced by a fan (not shown) that is provided with filters.

The enclosure 3 is provided with means for exhausting the sterile laminar stream, which means are arranged in such a manner as to form, under the packaging zone Z1, which buffer zone Z2 sucks in the laminar stream in which the flow is unidirectional, vertical, and downwards. In the buffer zone Z2 there exists a second pressure P2 that is lower than the first pressure P1 but higher than the surrounding pressure P. The exhaust means are arranged to ensure that the laminar stream exits the packaging zone Z1 without being disturbed. In this embodiment, the packaging zone Z1 and the buffer zone Z2 are physically separated by a perforated partition, specifically, a grid 12.

So as to enable the packaging zone Z1 to be pressurized while at the same time promoting vertical flow of the sterile air stream throughout the packaging zone Z1, the walls 5 include bottom edges in the buffer zone Z2 defining exhaust openings 13 above the floor 4. The exhaust openings 13 form the exhaust means. The first pressure P1 and the second pressure P2 are the result of an equilibrium between the feed rate via the ceiling and the leakage rate via the exhaust openings 13 and possibly other openings (e.g. entry or exit for the containers) in the side walls of the enclosure.

In order to promote undisturbed outward flow of the laminar stream from the packaging zone, the exhaust openings 13 are at a distance that is as far away as possible from the mesh 12. Similarly, the mesh 12 presents a perforation area that is as large as possible so as to ensure the stream continues to flow in laminar manner.

In this embodiment, the exhaust openings 13 are provided with respective flaps 18 making it possible to close the exhaust openings 13 in leaktight manner during cleaning and decontamination operations.

The table 11 of each machine forms at least a portion of the floor 4 of the enclosure 3 that includes openings for receiving the tables.

The installation further includes nozzles 15 for dispersing a washing substance that open out into the packaging zone Z1 and into the buffer zone Z2, and dispersing decontamination substances nozzles 16 that open out into the packaging zone Z1 and into the buffer zone Z2.

The feed-lines connecting the nozzles 15, 16 to the tanks containing the cleaning substance extend mainly in the buffer zone Z2. Thus, most of the elements disposed in the packaging zone Z1 are used for packaging, thereby making it possible to reduce the risk of pollution in the packaging zone Z1, by facilitating washing and decontamination thereof.

The installation also includes a recovery device 17 having a suction orifice opening out just above the floor 4 to remove the washing and decontamination substances. The installation further includes at least a tray for collecting substances, which tray extends into the buffer zone Z2 in order to convey the substances to the suction orifice of the extraction device 17. The floor 4 and/or the table 11 may also be of a shape adapted to promoting the flow of liquid towards the recovery device.

Naturally, the invention is not limited to the embodiments described and variants may be applied thereto without going beyond the ambit of the invention, as defined by the claims.

In particular, although the invention is described in an installation in which the various zones are subjected to two different pressures, an installation could be made with zones subjected to a greater number of different pressures and that are arranged relative to one another in such a manner as to promote the movement of air from the zones that need to be subjected to a highest degree of asepsis towards zones that are suitable for being subjected to a lesser degree of asepsis.

In practice, it should be noted that a small difference in pressure, of the order of approximately ten Pascals, is preferable so as to minimize air movements while opening a partition between two adjacent zones. Depending on circumstances, the difference in pressure between the two zones may be small or even marginal and simply be a result of head-losses in the laminar flow. The two zones may be defined by a physical boundary, as in the embodiment described, or they may extend contiguously without separation.

In addition, the exhaust openings may be replaced by extractors, so that turning the extractors off stops the flow of the laminar stream.

On at least one side of the enclosure, it is possible to provide a human intervention zone that is subjected to a vertical stream of sterile air. 

1. An aseptic packaging installation in individual containers, comprising a stand on which there is mounted an enclosure (3) that has a floor (4) with an overhead ceiling (6) and that receives at least one rotatable platform (7) in a packaging zone (Z1) subjected to a sterile laminar stream flowing vertically from the ceiling of the packaging zone at a rate that is adapted to establish in the packaging zone a first pressure (P1) that is greater than the surrounding pressure, the installation being characterized in that the enclosure is provided with laminar stream exhaust means for removing the laminar stream from the packaging zone via a buffer zone extending between the packaging zone and the floor.
 2. A packaging installation according to claim 1, including dispersion means for dispersing at least one cleaning substance and recovery means for recovering said substance, at least a portion of the dispersion means and the recovery means extending into the buffer zone (Z2).
 3. A packaging installation according to claim 2, wherein the dispersion means comprise washing substance dispersion nozzles (15) that open out into the packaging zone (Z1) and into the buffer zone (Z2).
 4. A packaging installation according to claim 2, wherein the dispersion means comprise decontamination substance dispersion nozzles (16) that open out into the packaging zone (Z1) and into the buffer zone (Z2).
 5. A packaging installation according to claim 1, wherein the recovery means (17) comprise at least one substance collection tray extending into the buffer zone (Z2). 